Annales Agriculturae Fenniae

Annales Agriculturae Fenniae Maatalouden tutkimuskeskuksen aikakauskirja Journal of the Agricultural Research Centre Vol. 23,1

Annales Agriculturae Fenniae JULKAISI JA PUBLISHER Maatalouden tutkimuskeskus Agricultural Research Centre Ilmestyy 4 numeroa vuodessa Issued as 4 numbers a year ISSN 0570-1538 TOIMITUSKUNTA EDITORIAL STAFF M. Markkula, päätoimittaja Editor P. Vogt, toimitussihteeri Co-editor E. Huokuna K. Maijala J. Sippola ALASAR JAT SECTIONS Agrogeologia et -chimica Maa ja lannoitus ISSN 0358-139X Agricultura Peltoviljely ISSN 0358-1403 Horticultura Puutarhaviljely ISSN 0358-1411 Phytopạthologia Kasvitaudit ISSN 0358-142X Animalia nocentia Tuhoeläimet ISSN 0517-8436 Animalia domestica Kotieläimet ISSN 0358-1438 JAKELU JA VAIHTO Maatalouden tutkimuskeskus, Kirjasto, 31600 Jokioinen DISTRIBUTION AND EXCHANGE Agricultural Research Centre, Library, SF-31600 Jokioinen This journal is selectively referred by Automatic Subject Citation Alert, Bibliography and Index of Geology American Geological Institute, Biological Abstracts of Bioscience Information Service, Bulletin Signaletique Bibliographie des Sciences de la Terre, Chemical Abstracts, Current Contents, Entomological Abstracts, Informascience Centre National de la Recherce Scientifique, Referativnyj Zhumal, Review of Applied Entomology (Series A. Agricultural) Commonwealth Institute of Entomology.

ANNALES AGRICULTURAE FENNIAE, VOL. 23: 1-7 (1984) Seria ANIMALIA NOCENTIA N. 115 Sarja TUHOELÄIMET n:o 115 FLYING PERIODS AND OVIPOSITION OF CABBAGE ROOT FLIES IN SOUTHERN AND CENTRAL FINLAND I. HAVUKKALA, J.K. HOLOPAINEN and M. VIRTANEN HAVUKKALA, I., HOLOPAINEN, J.K. & VIRTANEN, M. 1984. Flying periods and oviposition of cabbage root flies in southern and central Finland. Ann. Agric. Fenn. 22: 1-7. (Inst. of Pest Investigation, Agric. Res. Centre, SF=31600 Jokioinen, Finland.) Adult fly populations of Delia radicum (L.) and Delia floralis Fall. (Anthomyiidae) were monitored using yellow water traps and egg 'samples collected in soulhern (60 N) and central (63 N) Finland in 1981-1983. Weather markedly influenced the emergence pattern and flying activity of.both species. Intense oviposition can be expected after prolonged spells of unfavourable weather (low temperatures, rain or strong winds). When the spring is warm the 1 st generation of D. radicum appears in the last two weeks of May in southern Finland. In 1981 the 1 st generation of D. radicum was more abundant than the 2nd, but in 1982 the opposite was true. The oviposition of D. radicum was very scanty in central Finland in 1981. In southern Finland the first generation of D. radicum may oviposit on rape, which may be a reservoir for this pest. D. floralis had a longer flying period, from the beginning of July to the end of August. Further north, in central Finland its oviposition period was shorter, from the end of July to the end of August. The fly populations varied greatly seasonally, between generations and years, as well as between localities. The implications of the population phenology and the effect of weather on the timing of various control measures is discussed. Index words: cabbage root fly, Anthomyiidae, Delia radicum, Delia floralis, flying periocls,, oviposition, cabbage, swede, rape, reservoir, weather effects, population dynamics. INTRODUCTION Cabbage root flies, Delia radicum (L). and D. floralis Fall. are serious pests of crucifer vegetables in Finland (VARIS and TIITTANEN 1982). For the development of non-chemical, biological and integrated control methods it is important to know the phenology and oviposition periods of these pests. This information would also be useful in constructing an eventual prognosis system in order to reduce unnecessary insecticide applications. In Finland the cabbage root maggots of the first generation of D. radicum are mainly controlled preventively at the time_of planting. Reports on the seasonal occurrence of cabbage root flies in northern latitudes are few. KANERVO (1954) published egg counts of fort- 408400402h 1

nightly samples from the years 1941 and 1945-1949, but without information on the weather during the respective summers. VARIS (1967) published data on the emergence of fieldcollected pupae reared outdoors in 1958-1962, along with temperature curves. In this paper we report on the flight and oviposition periods of cabbage root flies in 1981 in southern and central Finland and in 1982-3 in southern Finland, with notes on the effect of weather on population dynamics and crop damage. MATERIAL AND METHODS The study area in the south of Finland in 1981-1982 was at the Agricultural Research Centre in Vantaa (Grid 27 E 668:39, latitude 60 15' N). The site' s in central Finland were in the Botanical Gardens, University of Kuopio (696:53, 62 54' N) 'and in Leppävirta (694:53), 15 km from Kuopio. The weather data is from the meteorological stations in Helsinki, Jokioinen and Kuopio (ANON. 1981, 1982, 1983). In 1981 a plot of 21 by 21 cabbage plants (early maturing variety Ditmarsker Midi Enkona) was planted on June 6. Details of the planting site are given in HAVUKKALA (1982a). In 1982 a larger plot (32 by 32 plants) was established on June 5 50 metres from the 1981 site. In 1983 a similar plot was planted in Jokioinen on June 4, situated 10 metres from the northern edge of a fallow field. In Lep'pävirta the site was a 3-are plot of cabbage variety Futura, planted on June 9 and in Kuopio a 2-are plot of variety Ditmarsker Midi Enkona planted on June 3. In Vantaa cabbage root flies were trapped using standard yellow water traps 6 cm high and 15 cm in diameter painted fluorescent yellow and filled with water containing detergent (cf. FINCH and SKINNER 1974). In 1981 an arrangement of 25 traps set in a square was used (HAVUKKALA 1982 b). The distance be- tween the traps was 5 metres, since this has been found to be the maximum effective zone of visual responses to ANC-baited traps (FiNcH et al. 1980). In May the traps were at the cabbage plot; after planting the traps were moved away 50 metres, towards a fallow field. In 1982 two rows of five traps 5 metres apart were used for fly monitoring. One trap row was 50 metres away from the cabbage plot, the other 150 metres away. In 1983 10 traps 5 metres apart and 50 metres away from the plot were used for monitoring. To save time only the males were determined as to species. Eggs were collected in Vantaa, Jokioinen, Kuopio and Leppävirta at 2-4 day intervals by removing soil to a depth of 2 cm within a radius of 5 cm of the plant stem and extracting the eggs by the flotation method (HuGHEs and SALTER 1959); 15-20 plants were sampled at a time. Some additional material was collected from two farms in Suonenjoki, central Finland (694:50), one conventionally cultivated farm with 50 ares of the late maturing variety 'Blue Top' and the other an organically managed farm with 1 are of mainly the variety 'Länsipohja'. For a more detailed description of the farms, see HOLOPAINEN (1983). 2

RESULTS The daily maximum temperature and precipitation clearly affected the yellow trap catches in southern Finland (Figs. 1-3). In 1981 in Vantaa May was warm and the peak of the first generation of D. radicum occurred on May 30 (Fig. 1). Later on the very rainy and cold weather in June reduced the catches markedly. The dry and warm period at the beginning of July coincided with the first population peak of D. floralis, which occurred in much lower numbers than the 1 st generation of D. radicum. The second generation of the latter was very small. In 1982 the weather was again favourable for the early emergence of D. radicum at the end of May, but in June cold weather reduced the numbers of flies caught (Fig. 2). The catches were c. one third of the level in 1981. D. floralis started its flight c. one week earlier than in 1981 and was trapped in much higher numbers than the lst generation of D. radicum. The low catches between the July 9 and 25 were due to the strong winds at that time, although the weather was otherwise favourable. The 2nd generation of D. radicum was much more, n ilt rh, Lft numerous than the previous year, reaching its peak at the end of July. In 1983 in Jokioinen the first generation of D. radicum was small and occurred later than the previous years due to the cool spring, but the 2nd generation was more'numerous than D. floralis (Fig. 3). arn L 11 Fig. 2. Catches of 'male cabbage root flies from standard yellow water traps in southern Finland in 1982, with daily precipitation and maximum air temperatures. L 11 n Fig. 1. Catches of male cabbage root flies from standard yellow water traps in southern Finland in 1981, with daily precipitation and maximum air temperatures. Fig. 3. Catches of male cabbage root flies from standard yellow water traps in southern Finland in 1983, with daily precipitation and maximum air temperatures. 3

The oviposition of D. radicum was at a low level in June 1981, with occasional peaks on rainless days (Fig. 4). Only after the emergence of the D. floralis population were eggs found in larger numbers. In 1982 the lst generation of D. radicum again laid few eggs on cabbage. At the end of June a random sample of 100 rape roots from a nearby field in Vantaa contained a total of 28 D. radicum larvae on 16 plants. The numbers of D. floralis eggs oviposited on cabbage were more than ten times the previous year, up to 100 eggs/plant. In 1983 the peak of oviposition occurred later in the summer, coinciding with a warm and rainless period at the beginning of August. In central Finland, in Kuopio and Leppävirta, oviposition was at a rather low level, between five and ten eggs/ plant (Fig. 5). Samples of these eggs were put into culture, and over 95 % of the emerged larvae proved to be D. floralis. The peak of oviposition occurred in the middle of August. At the two sites in Suonenjoki the flies laid many more eggs, up to 190 eggs/plant at the end of July (Table 1). ån KUOPIO 7.5 VANTAA 1901 10.0 7.5 5.0 KUOPIO -- - - 5.0 LEPPÄVIRTA - 1981 2.5 2. VANTAA 1982 10 20 30 10 20 30 9 19 29 8 JUNE JULY AUGUST SEPT. Fig. 5. Oviposition of cabbage root flies on cabbage in central Finland in 1981, with daily precipitation and maximum air temperatures. Table 1. Oviposition of cabbage root flies on an organically cultivated (01) and a conventionally cultivated (Cl) farm in Suonenjoki. Figures are mean numbers of eggs/plant ± S.E. (n = 10). For further details, see text. Date Farm 01 Farm Cl 7.5 JOKIOINEN 19 83 5.0 13,`.f, 2.5 10 20 JUNE 30 10 20 30 JU LY 19 29 AUGUST Fig. 4. Oviposition of cabbage root flies on cabbage in southern Finland in 1981-1983. 12. VI. 1,3 ± 0,90 0,2 ± 0,2" 18. VI. 1,5 ± 0,6 0,2 ± 0,2 28. VI. 0,5 ± 0,2 0,1 ± 0,1 2. VII. 0,4 ± 0,2 0,5 ± 0,3 8. VII. 26,3 ± 7,0 7,2 ± 2,4 20. VII. 155,9 ± 47,3 81,7 ± 34,6 23. VII. 194,0 ± 44,8 140,3 ± 31,6 31. VII. 63,8 ± 11,8 34,6± 6,3 6.VIII. 27,0 ± 12,1 25,7 ± 10,0 17.VIII. 19,6± 3,7 14,8± 6,3 " n = 5 4

DISCUSSION The trap catches of D. radicum males should closely reflect the flight activity of females (cf. DAPSIS and FERRO 1983, VINCENT and STEWART 1983), giving an indication of the intensity of oviposition to be expected. The same presumably holds true for D. floralis, too. Heavy rain may slightly reduce the attractivity of the trap when mud splashes on the lower outside edge of the vessel, and covers some of the attractive yellow colour. However, the large inner surface area remains clean and thus make this effect negligible. The traps were also cleaned every 2-3 days during rainy periods. On cloudy days the yellow colour is slightly less intense, but shis is compensated by the increased contrast with the background. Low temperatures and windless conditions reduce the evaporation of water vapour which attracts the flies, but the yellow colour accounts for at least 7/8 of the attraction in D. radicum (FiNcH & SKINNER 1982). It is concluded that the trap catches are representative of the flight activity at the trapping site. Weather is an important factor in the timing and intensity of egg-laying (ABU YAMAN 1961). In June 1981 the low level of oviposition in Vantaa was partly due to unfavourable weather, partly to the population peak having been passed by the planting time. The latter is supported by the very low numbers of the 2nd generation the same summer. In addition, the rainy weather in June provided the young seedlings with ample water, reducing wilting and helping the plants to compensate for root damage (cf. WRIGHT 1953). Therefore the mortality of the young seedlings caused by cabbage maggots was very low (<0,5 %, HAVUKKALA 1983). From the practical point of view, after warm springs it may be useful to delay planting time, if possible, in order to reduce attack. To assess the reliability of this pest control method more detailed data is needed of the local variation in the emergence patterns in relation to temperature sums (cf. FINCH and COLLIER 1983). A sharp rise in the oviposition of D. floralis and the 2nd generation of D. radicum can be expected after a prolonged period of rain, cold or very windy weather. If such periods coincide with the expected population peak this might be utilized by timing the control measures to immediately after such an unfavourable spell of weather. This is true in particular of the use of ash as an oviposition barrier (HAVUKKALA 1982 a), as ash is easily washed away by heavy rain. Such timing could be useful on swede, too, against D. floralis in central Finland, where this species cannot be controlled well by lindane dressing of seeds (VARis and DALMAN 1980). In 1982 the 1st generation of D. radicum was less abundant than the previous year, presumably owing to the small 2nd generation in 1981. Although oviposition on cabbage was not extensive, the second generation was surprisingly abundant. Apart from weather effects, this may have resulted from the oviposition of flies at the beginning of the summer on rape before the cabbage plants became available. MESSELIERE (1982) has recently reported that in France winter rape may be a reservoir for cabbage root flies, and the crop can even suffer heavily from root damage by maggots. Even if the cabbage may look healthy, plants with five or more cabbage root fly pupae already show a reduction of over 10 % in cabbage head weight (HAVUKKALA 1983). However, in central Finland, where spring mortality of young plants due to D. radicum is low it will often be possible to obtain satisfactory yields of the early maturing varieties of cabbage even without control, since the small larvae of D. floralis do not have time to affect the growth of plants too much before cropping. 5

Acknowledgments. - We thank Professor M. Markkula from the Institute of Pest Investigation, Agricultural Research Centre and Professor L. Kärenlampi from the Department of Environmental Hygiene at the University of Kuopio for facilities. Useful comments were provided by Sirpa Kurppa, Martti Markkula and Katri Tiitanen. Kerttu Lehtinen helped in the preparation of the figures. The study was financially supported by the National Research Council of Agriculture and Forestry of the Academy of Finland. REFERENCES Asu YAMAN, I.K. 1961. Natural control in cabbage root fly populations and influence of chemic'als. Medd. Landb. Hogesschool Wageningen 60: 1-57. ANON. 1981. Kuukausikatsaus Suomen ilmastoon. Ilmatieteen laitos. (Monthly review of Finnish climate. Institute of Meteorology.) 1982. Kuukausikatsaus Suomen ilmastoon. Ilmatieteen laitos. (Monthly review of Finnish climate. Institute of Meteorology.) 1983. Kuukausikatsaus Suomen ilmastoon. Ilmatieteen laitos. (Monthly review of Finnish climate. Institute of Meteorology.) DAPSIS, L.J. & FERRO, D.N. 1983. Effectiveness of baited cone and colored sticky traps for monitoring adult cabbage maggots: with notes of female ovarian development. Ent. Exp. & Appl. 33: 35-42. FINCH, S. & COLLIER, R.H. 1983. Emergence of flies from overwintering populations of cabbage root fly pupae. Ecol. Ent. 8: 29-36. & SKINNER, G. 1974. Some factors affecting the efficiency of water-traps for capturing cabbage root flies. Ann. Appl. Biol. 77: 213-226. & SKINNER, G. 1982. Trapping cabbage root flies in yellow traps baited with plant extracts and with natural and synthetic isothiocyanates. Ent. Exp. & Appl. 31: 133-139., FREULER, J. & STÄDLER, E. 1980. Trapping Hylemya brassicae adults. Integrated control on Brassica crops. W.P.R.S. Bulletin 1980/111/1. HAVUKKALA, I. 1982 a. Deterring oviposition of the cabbage root fly, Delia radicum (Diptera: Anthomyiidae) by non-chemical methods. Acta Ent. Fenn. 40: 9-15. '1982 b. Odour source finding behaviour of Delia brassicae in the field. Proc. 5th Int. Symp. Insect-Plant Relationships, Wageningen. p. 397-398. Pudoc. 1983. Naturliga bekämpningsmetoder mot kälflugor. (Non-pesticide control methods against cabbage root maggots). Växtskyddsnotiser 46: 90-93. HOLOPAINEN, J.K. 1983. Carabid beetles (Col., Carabidae) associated with cruciferous crops in organic and conventional farms in Central Finland. Savonia 6: 19-27. HUGHES, R.D. & SALTER, D.D. 1959. Natural mortality of Erioiscbia brassicae B. (Diptera: Anthomyiidae) during the immature stages of the first generation. J. Anim. Ecol. 28: 231-241. KANERVO, V. 1954. Grönsaksflugornas biologi och bekämpning. Nord. Jordbr.forskn. 36: 333-338. MESSELIERE, C. DE LA 1982. Les attaques de la mouche de chou sur colzas d'hiver. Phytoma 334 (Janvier): 22. VARIS, A.-L. 1967. Studies on the biology of the cabbage root fly (Hylemya brassicae Bouche) and the turnip root fly (Hy/emya flordis Fall.). Ann. Agric. Fenn. 6: 1-13. & DALMAN, P. 1980. The efficacy of lindane and dimethoate against cabbage maggots in Finland. J. Sci. Agr. Soc. Finland 52: 7-13. & TIITTANEN, K. 1982. Insect pests of vegetables in Finland and methods for their control. Acta Ent. Fenn. 40: 38-42. VINCENT, C. & STEWART, R.K. 1983. Evaluation de deux types de piege pour le depistage des adultes de la mouche de chou, Hylemya (Delia) brassicae (Wiedemann). Ann. Soc. Ent. Quebec 26: 41-50. WRIGHT, D.W. 1953. The assessment of damage caused to some brassica crops by the cabbage-root fly. Ann. Appl. Biol. 40: 607-611. Manuscript received September 1983 Ilkka Havukkala Agricultural Research Centre Institute of Pest Investigation SF-31600 Jokioinen, Finland Jarmo K. Holopainen University of Kuopio Ecological Laboratory, Department of Environmental Hygiene SF-70211 Kuopio 21, Finland Marjatta Virtanen University of Helsinki Department of Zoology SF-00100 Helsinki 10, Finland 6

SELOSTUS Kaalikärpästen lentoajoista ja muninnasta Etelä- ja Keski-Suomessa ILKKA HAVUKKALA, JARMO K. HOLOPAINEN ja MARJATTA VIRTANEN Maatalouden tutkimuskeskus Kaalikärpäsen (Delia radicum) ja ison kaalikärpäsen ( D. floralis) esiintymistä ja munintaa seurattiin keltamaljapyydysten avulla ja ottamalla maanäytteitä 1981-1983 Etelä-Suomessa (Vantaa, Jokioinen) ja Keski-Suomessa (Kuopio, Leppävirta, Suonenjoki). Sää vaikutti suuresti molempien lajien esiintymiseen ja munintaan. Pitkien epäedullisten sääjaksojen jälkeen muninta on usein hyvin runsasta, mikä tulisi ottaa huomioon torjunnan ajoittamisessa. Kaalikärpäsen ensimmäinen sukupolvi lensi Etelä-Suomessa kahtena lämpimänä keväänä jo toukokuun kolmannella viikolla. Tällaisina vuosina voi olla mahdollista vähentää kaalikärpästuhoja siirtämällä kaalin taimien istutusta myöhäisempään ajankohtaan. Muninnan pääosa rajoittuu noin kahden ja puolen viikon ajalle. Etelä-Suomessa kaalikärpänen munii myös rapṣille, mikä voi lisätä toisen suku- polven esiintymistä jonkin verran. Kaalikärpästä esiintyi hyvin vähän Kuopiossa ja Leppävirralla. Ison kaalikärpäsen lentoaika Etelä-Suomessa oli pidempi, heinäkuun alusta elokuun loppuun; loppukesällä se lentää yht'aikaa kaalikärpäsen toisen sukupolven kanssa. Keski- Suomessa ison kaalikärpäsen lentoaika oli lyhyempi ja alkoi heinäkuun loppupuolella. Keski-Suomessa iso kaalikärpänen aloittaa munintansa niin myöhään, että esim. lantun siementen peittaus lindaanilla ei enää tehoa toukkiin. Toisaalta aikaiset kaalilajikkeet voivat siellä välttyä vioitukselta, jos ne on istutettu kyllin aikaisin. - Molempien lajien esiintymisessä on suuria ajallisia ja paikallisia eroja. Kosteusolosuhteet vaikuttavat oleellisesti tuhojen ilmenemiseen: sateisena kesänä selviytyvät nuoret taimet kuihtumatta suuristakin kaalikärpästoukkien aiheuttamista juuristovaurioista. 7

ANNALES AGRICULTURAE FENNIAE, VOL. 23: 8-25 (1984) Seria ANIMALIA DOMESTICA N. 67 Sarja KOTIELÄIMET n:o 67 FEEDING REGIMEN AS A MEANS TO REDUCE THE USE OF PROTEIN IN POULTRY PRODUCTION TUOMO KIISKINEN KIISKINEN, T. 1984. Feeding regimen as a means to reduce the use of protein in poultry production. Ann. Agric. Fenn. 23: 8-25. (Agric. Res. Centre, Inst. Anim. Husb., 31600 Jokioinen, Finland.) Three nutritional experiments were conducted using low energy, low protein (LE-LP) diets for replacement chickens and broilers and phased diets for laying hens. The LE LP grower diets contained oats as the sole grain and their supplementary protein originated from either fish and soybean meal or pea meal. Two and threephase feeding systems were compared with consrant feeding on laying hens. The phased diets contained either chiefly fish and soybean meal or domestic protein sources as supplementary protein. Six different combinations of ME and CP, including two ME:CP ratios (69 and 62 KJ/g CP) and two supplementary protein compositions were used in the third experiment on finishing broiler chicks. The dietary treatments during the rearing period had no significant effect on the live weight of pullets or their subsequent laying performance. Up to 120 g protein per pullet could be saved by using the LE-LP diets (PG0,05). Phased feeding and the replacement of imported protein chiefly by domestic protein did not significantly affecr the performance of laying hens. The phased feeding systems saved up to 36 g protein per kilogram of eggs (P <0,05). The results support the view that phased calcium and possibly also phosphorus is useful for egg shell quality. The growth rate of broiler chicks was satisfactory on ali the ME CP combinations. No significant differences were ascertained between the two ME:CP ratios and supplementary pi-otein treatments. Consumption and conversion of feed and ME were higher (P <0,05) on the higher ME:CP ratio than on the lower ratio. The results confirm that it is advantageous to decrease both the dietary energy and protein level to mainrain the optimum level of efficiency. The results of the present study suggest that it is possible to maintain a satisfactory production level by diluting the diets and by combining their use with the production phase. These feeding regimens save mainly protein, which measure can be necessary and economic in certain circumtances. Index words: replacement chickens, laying hens, broiler chicks, low energy, low protein diets, phased feeding, protein sources, egg production, growth rate, feed consumption, mortality. 8

INTRODUCTION Studies dealing with ways of reducing of poultry feeding costs have become more and more important. Numerous feeding tests have been conducted to determine the level of energy and protein needed in a diet for the economically optimum performance of poultry of a given age. The nutrient requirements of the growing White Leghorn pullet are not well defined with regard to production goals, which are ultimately associated with subsequent laying performance. A number of quantitative and qualitative feed restriction methods have been tested to decrease body weight and to delay sexual maturity of the pullets or to reduce the cost of feeding and to achieve an improvement in subsequent laying performance. Most of the qualitative restriction studies have been performed with either low energy (LE) or low protein (LP) diets and only few with LE LP diets (BERG and BEARSE 1958, BERG 1959, BULLOCK et al. 1963, LILLIE and DENTON 1966, ARMAS et al. 1972, KONDRA et al. 1974, PETER et al. 1976, CARLSSON and NELSSON 1981). Dietary fillers or inert substances like oat hulls, wheat bran, alfalfa meal, ground wheat straw, sand or kaolin have often been used to dilute the diets in these studies. Nutrient dilution has not generally given satisfactory results in the reduction of body weight or the delaying of sexual maturity of the pullet. The pullets generally offset the treatment by increased consumption when feed is available. Sand and clay as dietary fillers have been proved to improve the feed and energy utilization of poultry (HARms and DAMRON 1973, HOOGE et al. 1977, OLOUYEIVII et al. 1978, SELLERS et al. 1980). The use of LE LP diets during the growing period has not affected the subsequent laying performance. Phased feeding of layers means adjusting the dietary nutrient content to correspond with the changing production stages. This feeding re- 2 408400402h gime usually concerns protein because of its economic importance, and most of the systems used periodically adjust the amounts of protein downward and calcium upward during the laying cycle. The effect of low protein content in the diet during the pr.oductive period of laying hens has been reported to have little effect on their egg production unless severe reductions are made or in particular, if diets are supplemented with methionine and lysine (OwiNGs 1964, FISHER and MORRIS 1967, AITKEN et al. 1973, FERNANDEZ et al. 1973, KOLSTAD and LIEN 1974, KASHANI 1976, HAMILTON 1978, EL BOUS' HY and MUILWIJK 1978). There is controversy over whether or not layers should be fed constant protein or amino acid levels during their whole production period or whether a phased feeding programme should be used. JENNINGS et al. (1972) reported that birds require more protein at the end of the laying year than at the beginning to sustain a given level of output. According to HARMS (1979), the amino acid requirements of laying hens do not decrease with age: however, the levels of amino acids can be lowered because the original recommendations contained a considerable margin of safety. MC- NAUGHTON et al. (1980) reported that a suitable phased feeding program offers an added benefit of decreasing dietary protein costs with maximum layer performance. The calculations of FEID and MAIORINO (1980) refer to a decreased protein requirement as the laying period progresses. Increasing dietary calcium towards the end of the production period is aimed at. improvement of shell quality, and also decreases overconsumption of feed. According to OUES- TERHOUT (1981) phased feeding'of protein and calcium saves energy consumed per gram of egg and is effective in improving shell quality in older hens. It has also been proposed that phosphorus should be phase fed (HARmS 1979, 9

MIKAELIAN and SELL 1981). The highest rate of live weight gain and best feed conversion does not necessarily give the highest profitability in broiler production. Some studies have shown that low-protein broiler diets enriched with methionine and lysine can ensure ^good, though not maximal, performance by the birds (BRETTE and PICARD 1974, BORNSTEIN and LIPSTEIN 1975, LIP- STEIN and BORNSTEIN 1975, FONSECA et al. 1978, PROUDFOOT and HULAN 1978, KORE- LESKI and RYS 1979). In any case the lower protein level means better protein conversion (FLACHOWSKY and HENNING 1973, KORELASKI and RYS 1979, EL. BOUSHY et al. 1979). On the other hand, the increased energy :protein ratio increases fat deposition in broiler carcasses (FLACHOwsKv and jeroch 1973, FONSECA et al. 1978, KIRCHGESSNER et al. 1978, ROBBINS 1981, BRAY 1982). The present study included three experiments with LE LP diets. The objects of these experiments were to investigate the potential for reducing the input of protein and the need supplementary protein sources in order to improve the economy of poultry feeding. This was accomplished by feeding LE LP diets to replacement chickens and broiler chicks and phased diets to laying hens. The majority or ali fish and soybean meal was replaced with domestic protein sources (rapeseed meal, pea meal, Pekilo SCP product) to compare bird responses to the feeding regimens. MATERIAL AND METHODS Animals and management Experiment 1. Day-old female White Leghorn chicks of a commercial strain (SK 51) were randomly distributed into rearing cages in threetier batteries. The birds were kept in the middle tier for the first six weeks and then divided between the three tiers. Seventeen chicks were placed in each cage (1 m 2). At the end of the growing period (18 weeks), pullets were transferred to cages in the layers' house. The laying period lasted approximately eleven months (11 x 28 days). The housing conditions during both the rearing and laying periods were conventional and,controlled (KiisKINEN 1983 a). Experiment 2. The trial was conducted on 1260 laying hens (WL, strain SK 51) from 20 to 68 weeks of age (i.e. twelve periods of 28 days). The environmental conditions were as above (Expt. 1). Experiment 3. 1800 sexed day-old Pilch broiler chicks were placed in 36 floor pens with 50 birds (25 males, 25 females) each (6 m2). The chicks were housed for six weeks under the conditions described by KIISKINEN (1983 b). Experimental design and diets Experiment 1. Three main treatments were planned for the rearing period (Table 1). The control group received 20 % crude protein (CP) and 11,0 MJ/kg metabolizable energy (ME) in the starter diet (0-6 weeks) and 15 % CP and 10,9 MJ/kg ME in the grower diet (7-18 weeks). Two treatment groups were offered diets with reduced levels of ME and CP (LE LP 1, LE LP 2). Both LE LP groups were fed the same starter diet (10 MJ/kg, 18 % CP) and different grower diets: 10,1 MJ/kg, 13,5 % CP (LE LP 1); 9,7 MJ/kg, 12 % CP (LE LP 10

Table 1. Composition and calculated contents of diets in Expt. 1. Fish meal Meat and bone meal Soybean meal Pea meal Starter diets (0-6 weeks) Control 6-17 _ LE-LP') 5-15 - Grower diets (6-18 weeks) LE-LP 1 LE-LP 2 Control subgroup 1/ subgroup 2 3 2/0-4/0 0/20 Layer diet 6,5 2/0-0/10 Barley 43,5 28,5 52,4-52,7 Oats 30 40 35 86,7/72,5 85,6/78,5 26 Rapeseed oil 0,5 0,5 - - - 0,5 Dicalcium phosphate 1,5 1,5 1,8 2,1 2,1 Limestone, ground 0,7 0,7 0,5 0,5 0,5 6,5 Salt 0,35 Vitarnin premix2) 0,17 0,17 0,15 0,15 0,15 0,15 Mineral premix3) 0,25 DL-methionine 0,03-0,03 0,03 0,06/0,10 0,10 0,05 Sand - 8 _ 4 8 - ME MJ/kg 11,0 10,0 10,9 10,1 9,7 10,3 Crude protein % 20 18 15 13,5 12 15,5 Methionine % 0,39 0,37 0,30 0,30 0,30 032 Lysine % 1,13 1,00 0,73 0,65 0,54 0,76 LE-LP = low energy-low protein Supplies per kilogram of starter/grower and layer diet: 17000/15000 11.1 vitarnin A, 2000/1700 IU vitamin 133, 23/20 mg vitamin E, 1,2/1,0 mg vitamin K, 3,5/3 Mg riboflavin, 1,7/1,5 mg pyridoxine, 20/18 mg niacin, 12/10 pg B12, 0,33/0,3 mg folic acid, 550/500 mg choline chloride, 5/5 mg Carophyll yellow (10 %) Supplies per kilogram of diet: 20 mg Fe, 45 mg Zn, 50 mg Mn, 4 mg Cu, 0,7 mg Co, 0,5 mg I, 0,1 mg Se. 1/0 3 7,5, Table 2. The experimental design of Expt. 2. Group number Number of phases Phase number Age of birds (weeks) Dietl) number Calculated CP (%) ME (MJ/kg) 1 1 20-68 1 15,5 10,6 2 and 3 2(a) 1 20-44 1 "(a) 2 45-68 4 and 5 13 9,7 4 and 5 "(b) 1 20-44 2 and 3 14 10,4 "(b) 2 45-68 6 and 7 12,5 9,7 6 and 7 3 1 20-36 1 15,5 10,6 2 37-52 2 and 3 14,0 10,4 1, I 3 53-68 6 and 7 12,5 9,7 1) Diet numbers 3, 5 and 7 contained domestic protein supplements. 2). In addition to this the LE-LP groups were devided into two subgroups and given either fish and soybean meal (FM-SBM) or pea meal (PM) as supplementary protein. The low energy concentrations were produced using sand as a dilutant and oats as the sole grain. The content of PM was 10 or 20 % depending on the dietary protein level. The methionine content of the grower diets was adjusted to the same level regardless of their energy and protein concentrations. Each main group included 24 replicate cages of 17 chicks in ord;er to check body weight and mortality. Feed consumption was measured per tier (6 cages), with four replicates per main treatment. During the laying period 12 replicates of 30 hens were.allotted to each of the three main rearing treatments. Experiment 2. This trial contained four main treatments planned according to the number of laying phases and dietary contents of CP and ME (Table 2). One treatment group (1) was fed a constant diet during the whole 11

laying period. The feeding of the other groups (2-7) was phased for two or three periods of 24 and 16 weeks, reducing the dietary CP, ME and phosphorus levels and increasing the calcium content towards the end of the experiment. Two different systems were used in two-phase feeding. They differed mainly in the dietary protein contents which were 15 and 13 %, and 14 and 12,5 % during the first and second phases, respectively. Ali phased feeding treatments consisted of two supplementary protein treatments which differed in the protein source (Tables 2 and 3). The first (groups 2, 4, 6) utilized imported protein ingredients (IP) and the second (groups 3, 5, 7) used mainly domestic ingredients (DP). In the formulation of the diets more oats and oat hulls were used to produce the low energy concentrations of the diets for the later laying phases (Table 3). The increased concentration of limestone also contributed to this end. The purpose of the elevated concentration of calcium and reduced level of phosphorus in the later phases of the diets was to help maintain the quality of the egg shells. Each group had six replicates of 30 hens each. Experiment 3. This experiment on broiler chicks was performed at the age of 21-43 days. The experimental design included six combinations of ME (MJ/kg) and CP (%) 10,5/15, 10,5/17, 1151/16, 11,1/18, 11,7/17, 11,7/19 (Table 4), thus comprising three ME levels and two ME:CP ratios (69 and 62 MJ/g protein). Each combination also used two different compositions of supplementary protein, the first consisting of imported protein (FM SBM = IP) and the second including mainly domestic feedstuffs and fish meal (DP). Thus the total number of groups was twelve with three replicate pens each. During the first three weeks ali groups were fed a commercial starter feed which contained 22 % CP and 12,6 MJ ME/kg. The ME contents of the finisher diets were arranged using different proportions of cereals and fat supplements, using oat hulls and wheat bran as dilutants. The same supplementary level of methionine was used in ali diets. Table 3. Composition and calculated contents % of the layer diet in Expt. 2. ME MJ/CP % Diet ar 10,6/15,5 2 10,4/14 3 4 10,1/13 5 9,7/12,5 6 7 Fish meal 3 2 2 1,5 Meat and bone meal 3 3 3 3 3 2 2 Soybean meal 7 4-3 - 6 - Rapeseed meal - - 3,5 4-4 Pea meal - - 2 3-4 Pekilo - 1-1 - 1 Barley 60,5 42 40,5 41,5 40,5 35,3 36 Oats' 18,5 41 40 40 39,5 41,5 40 Oat hulls - - 2 5 3 Rapeseed oil 0,5 0,5 0,5 0,5 0,5 0,5 0,5 Limestone, ground 5,5 5,5 5,5 6,8 6,8 7,5 7,5 DicalCium phosphate 0,5 0,5 0,5 0,2 0,2 0,5 0,5 Salt 0,4 Vitamin premixi) 0,5 Mineral premix1) 0,5 > DL-methionine 0,035 0,07 Methionine calc. 0,30 0,30 0,30 0,28 Lysine calc. 0,76 0,66 0,59 0,57 Calcium calc. 2,85 2,85 3,20 3,40 Avail. phosphorus cald. 0,45 0,45 0,40 0,38 12 1) Same supplies as in the layer diet of Expt. 1.

Table 4. Composition % of the broiler finisher diets (3-6 weeks) in Expt. 3. ME MJ/C 1 % Diet nurnber 10,5/15 10,5/17 1 2 3 4 11,1/16 5 6 11,1/18 7 8 11,7/17 11,7/19 9 10 11 12 Fish meal 5 5 4 4 4,5 4,5 4 4 4 4 4 4 Soybean meal 8 15 11-17,5-15 - 21 - Rapeseed meal 5 10 7,5 12,5 10 _ 12,5 Pea meal 2 4 3 5-6 - 10 Pekilo 1 4 3-5 - 5 _ 8 Wheat 10 10 10 10 20 20 20 20 Barley 38 36 42 38 45 47 45 40 54,5 47,7 48 37,3 Oats 38 35,5 30 27,7 21 10,5 16 10,7 - - - - Wheat bran 10 7 8-6 - - - Oat hulls 6 4 3-2 - - - Rapeseed oil 1 1,5 1 1,5 1,5 2,5 1,5 3 2,5 3,5 3 4,5 Dicalc. phosp. 1,6 1,4 1,6 1,4 1,6 1,4 1,6 1,4 1,6 1,4 1,6 1,3 Limestone, ground 0,8 3.> Salt 0,33 Vitamin premixl) 0,5 Mineral premix2) 0,5 DL-methionine 0,07 Methionine calc. % 0,39 0,40 0,38 0,42 0,40 0,43 Lysine calc. % 0,83 0,96 0,90 1,02 0,95 1,10 KJ ME/g protein 69 62 69 62 69 62 Supplies per kg of diet: 17500 IU vitamin A, 1700 IU vitamin D3, 24 mg vitamin E, 1,5 mg vitamink, 3,5 mg riboflavin, 1,5 mg pyridoxine, 22 mg niacin, 15 pg 1312, 0,6 mg folic acid, 500 mg choline chloride Same supplies as in Expt. 1. Measurements and post mortem investigations Experiment 1. The body weight of chicks was recorded as the total weight of the birds in each cage (replicate), at one day, six weeks and 12 and 18 weeks of age. Feed consumption was also recorded during the same periods, but the measurements were performed per tier (6 cages). Egg production and mortality records were maintained on a daily basis and feed consumption and egg weight according to four-week periods. The final body weight of the hens was measured at 64 weeks of age. The Haugh unit and specific gravity of the eggs were measured three times at 27, 41 and 63 weeks of age. Experiment 2. Egg production, feed consumption and mortality were recorded as in Experiment 1. The birds were weighed at 20 and 68 weeks of age and the egg quality te sts were performed at 26, 46 and 66 weeks of age. At the end of the trial, the thyroid glands and livers from 30 randomly selected birds from each supplementary protein treatment (IP and DP) and the abdominal fat from 30 hens each from the one and two-phase (2 b) feeding treatments were removed and weighed. Approximately half of the dead birds were sent to the National Veterinary Institute for diagnosis. Experiment 3. The following traits were measured and recorded: total weight of day-old chicks per pen; individual weights of chicks at three and six weeks of age; feed consumption per pen between weighings, total slaughter weight of both sexes per pen, mortality and incidence of leg weakness per pen, thyroid, liver and abdominal fat weight of eight birds and predictes value for abdominal fat of 42 birds per ME-CP combination by caliper technique (PYm and THOMSON 1980).. In the slaughterhouse, eight sample carcasses taken from each of three rapeseed meal levels (0, 5-7,5 and 10-12,5 %) for a taste panel test. The carcasses were handled and the test performed using 15 tasters as described earlier (KiisKINEN 1983 b). 13

Analyses, ME determinations and statistics Proximate analysis was performed for each supplementary protein source and each lot of the experimental diets. Amino acid contents of the supplementary proteins and a common sample of each diet were determined with a gas chromatograph (HP 1570). Calcium was analysed with an atomic absorption spectrophotometer and phosphorus with a photometer after a colour reaction with ammonium vanadate. Total glucosinolates in rapeseed meal were determined as their desulphonated silyl derivates using quartz capillary column (50 m, SE 30, 170-270 C). The analysis was performed in the Department of General Chemistry of the Faculty of Agriculture and Forestry of the University of Helsinki. Tannins in the pea meal were analysed using the FOLIN-DENIS method in the State Institute of Agricultural Chemistry (HERRMANN 1963). The ME concentrations of the layers' diets in Experiment 2 were determined experimentally using difference method of total excreta collection (5 hens per diet). The data for each experiment were analysed using analysis of variance, and differences in treatment means were studied by Tukey and t- test (STEEL and TORRIE 1960). RESULTS Analyses of ingredients and diets Proximate analyses of fish meal revealed that its crude protein content was low (55 %) and ether extract correspondingly high (12,3 To; Table 5). Rapeseed meal also had a relatively low content of crude protein (32,6 %) and, according to the total content of glucosinolates (35,4 pmol/g fat free dm) the RSM used can be classified as an HG meal (OLsEN and SORENSEN 1980). Pea meal contained 0,7 % tannins and the meal apparently derived from Table 5. Chemical cornposition of the protein ingredients. Fisb meal Meat and bone meal Soybean meal Rapeseed meall) Pea meal2 ) Pek ilo Proximate analysis (%) dry matter 86,7 88,5 88,2 88,4 85,7 88,3 crude protein 55,0 42,0 44,3 32,6 24,2 53,6 ether extract 12,3 7,4 1,5 4,5 1,1 1,8 crude fibre - 6,1 12,5 5,8 5,6 ash 18,9 36,9 5,6 7,1 3,0 3,4 Amino acids (g/16 gn) Methionine 2,1 1,3 1,6 1,9 0,7 1,5 Cystine 0,6 0,4 1,1 1,3 1,2 0,6 Lysine 6,1 4,5 6,3 5,7 6,0 6,8 Arginine 4,5 7,6 7,8 5,9 8,5 6,6 Histidine 1,5 1,0 2,2 2,0 2,9 2,2 Leucine 7,0 5,7 7,8 7,2 6,4 6,9 Isoleucine 4,0 2,6 3,8 5,3 3,3 4,1 Phenylalanine 3,7 3,1 5,4 3,9 4,0 4,1 Tyrosine 2,9 1,8 4,0 3,0 3,0 3,4 Threonine 3,7 3,0 3,9 4,9 2,9 4,3 Valine 4,5 3,5 4,3 6,6 3,6 4,9 Glycine 7,1 14,0 4,3 4,8 3,8 4,3 Calcium (%) 3,63 15,2 - - Phosphorus (%) 2,63 7,0 - _ Tomi glucosinolates 35,4 pmolig for free drn Tannins 0,7 '11, 14

food cultivars (AuLiN 1979). The cystine level in the analysed amino acid contents of the supplementary proteins was lower than the table values in ali cases. The analysed CP values of the diets in Experiments 1 and 2 were without exception lower than the calculated values, mainly as a result of the low protein content of FM (Table 6). The contents of methionine and lysine in the diets of the above-mentioned experiments were also lower than expected. The determined ME values of the layer diets in Expt. 2 exceeded the calculated values by 0,2-0,3 MJ. Performance of birds Experiment 1. Feeding with the LE-LP starter diet resulted in no significant reduction in average body weight at six weeks of age as compared with the control diet (Table 7). The consumption of the LE-LP starter diet was approximately 7 % higher (P < 0,05) than that of the control diet but the relationship in energy and protein intake was reverse, although the 2 and 3 % lower. ME and protein intakes of the LE-LP groups did not significantly differ from those of the control group. The feeding regin-ien had no significant effect on weight gain from 6 to 19 weeks of age, but feed intake was significantly higher (P < 0,05) in the LE-LP groups than in the control group. The consumption of ME and protein during this period decreased in the LE-LP groups compared to the control group and the total protein intakes during the rearing period were 1064, 1021 and 943 g (P<0,05) in the contro-1, LE-LP 1 and LE-LP 2 groups respectively. Pea meal as the sole supplementary protein source in the LE-LP grower diets did not significantly affect growth or feed intake. Mortality was not significantly affected by the feeding regimens during the starting or growing period (Table 7). The use of low energy and low protein levels or PM as the sole supplementary protein source during the rearing period of pullets did not affect production, mortality or egg quality during the subsequent laying period (Table 8, Fig. 1). The hens of the PM groups consumed slightly less feed and protein (P<0,05) and gained less weight (P<0,05) than the hens of the FM-SBM groups. Table 6. Average analytical values of the diets (Experiments 1-3). Dry matter Crude protein Ether extr. Methionine Lysine Arginine Isoleuc. Threonine Calcium Phosphorus Expt. 1 Starters Control 87,1 18,4 4,1 0,37 0,99 1,04 0,98 0,64 0,84 0,77 LE-LP 83,2 16,5 4,0 0,33 0,91 1,02 0,99 0,68 0,84 0,72 Growers Control 87,8 14,8 3,0 0,28 0,70 0,80 0,50 0,44 0,81 0,73 LE-LP 1 89,0 13,3 3,9 0,26 0,63 0,84 0,61 0,43 0,80 0,73 LE-LP 2 89,3 11,6 3,9 0,25 0,55 0,71 0,49 0,35 0,78 0,72 Layer diet 88,5 14,6 3,5 0,26 0,69 0,86 0,70 0,55 2,90 0,69 AME N MJ/kg ±SD Expt. 2 Layer diet 1 88,1 14,5 3,3 0,26 0,70 0,81 0,55 0,52 2,83 0,71 10,85±0,17 " 2 and 3 88,2 13,0 3,8 0,26 0,55 0,70 0,64 0,49 2,85 0,72 10,62±0,15 " 4 and 5 88,7 12,0 3,7 0,23 0,46 0,67 0,46 0,42 3,02 0,62 10,37±0,15 " 6 and 7 88,9 11,6 3,6 0,23 0,51 0,59 0,42 0,39 3,24 0,60 10,00±0,11 Expt. 3 Broiler finisher " 1 and 2 86,9 14,9 4,5 0,39 0,81 0,99 0,65 0,52 0,90 0,82 " 3 and 4 86,2 16,9 4,5 0,40 0,87 1,05 0,81 0,62 0,85 0,78 " 5 and 6 86,4 16,0 4,7 0,42 0,87 0,92 0,99 0,51 0,80 0,75 " 7 and 8 86,7 18,2 4,6 0,42 0,93 1,15 1,08 0,56 0,85 0,83 " 9 and 10 86,1 17,0 5,2 0,40 0,82 0,94 1,10 0,53 0,85 0,76 "11 and 12 85,9 18,6 6,0 0,43 1,10 1,30 1,26 0,63 0,89 0,81 15

Table 7. Performance of the chickens during the rearing period (Expt. 1). ME/CP in starter " in grower Body weight (g) 6 weeks 12 " 18 " Control 11,0/18,4 10,9/14,8 470 1042 1329 LE-LP 1 2 10,0/16,5 10,0/16,5 10,1/13,3 9,7/11,6 464 1028 1314 457 1027 1305 FM-SBM 1 ) PM2 ) 10,0/16,5 10,0/16,5 9,9/12,5 9,9/12,5 461 1033 1309 460 1022 1309 Feed intake (kg/bird)4) 0-6 weeks 1,15a 1,23b 1,23b 1,26 1,21 0,012 6-12 " 2,90a 3,05b 3,21c 3,11 3,14 0,019 12-18 2,86a 3,09b 3,19b 3,08 3,20 0,031 0-18 6,91a 7,37b (7,02)7,63b (7,02)7,45 (6,98)7,55 (7,07)0,045 Energy intake (MJ ME/bird) 0-6 weeks 12,60 12,34 12,34 12,58 12,10 0,128 6-12 " 31,68 30,95 30,99 30,80 31,14 0,594 12-18 " 31,16 31,32 30,87 30,50 31,70 0,313 0-18 " 75,44 74,61 74,19 73,87 74,93 0,456 Protein intake (g/bird) 0-6 weeks 211 204 204 208 200 2,1 6-12 " 430a 406b 370c 390 386 2,5 12-18 4230 411a 369b 386 393 3,7 0-18 10640 1021b 943c 984 979 5,7 Mortality (%) 0-6 weeks 5,8 6,5 4,7 5,4 5,8 0,69 6-18 " 0,5 0,2 0,8 0,5 0,6 0,15 FM-SBM =- fish and soybean meal PM = pea meal SE = standard error of mean a-c Means with a different superscript letter within a row are significantly different (P < 0,05). If no letters are used the differences are non-significant. Figures in parenthesia show feed intake minus sand content. SE3) 2,1 3,5 4,8 100-100 - 80-80 - Hen day prod. % 60-40 - 20 Period 10 12 Control LE - LP 1 LE - LP 2 Fig.l. Egg production of pullets during the laying period (Expt. 1). 60 0; on 40-4, 20-0 2 4 6 8 10 12 Period Fig. 2. Egg production To in Expt. 2. On* phaa 1.o..hans(!1 1 Tro phagez<b) Experiment 2. With regard to the parameters of egg production no significant differences were ascertained between the treatments (Table 9). The average egg weight of the phased groups was, however, 0,7-1,1 g lower than that of the control group. The hen-day production curves of the constant and phased feeding groups were fairly similar (Fig. 2). Feed consumption in the two-phase group (2 b) which received diets with the lowest ME and protein concentrations was significantly higher (P < 0,05) than that in the other groups. This 16

Table 8. Performance of the laying hens and egg quality as a response to the dietary treatments during the rearing period (Expt. 1). Dietary regimen ontrol LE 1 LP 2 FM-SBM PM SE Age at 50 % laying days 169 170 171 170 171 0,40 Egg output kg/housed hen 12,68 12,88 12,69 12,73 12,85 0,080 % (hen-day) 74,3 75,6 75,1 75,5 75,3 0,35 g/hen/day 42,2 42,7 42,7 42,9 42,6 0,20 Egg weight g 56,8 56,4 56,9 56,8 56,6 0,10 Feed intake g/h/d 113,5 114,7 113,9 115,3 113,3 0,44 kg/kg eggs 2,69 2,69 2,67 2,69 2,66 0,011 Protein intake g/h/d 16,4 16,5 16,4 16,7 16,3" 0,06 g/kg eggs 388 388 385 389 384 1,6 ME intake KJ/h/d 1172 1185 1176 1191 1170 7,2 MJ/kg eggs 27,80 27,81 27,50 27,78 27,54 0,13 Final body weight g 1865 1875 1847 1883 1841 8,0 Weight gain % 39,52 41,9' 39,5a 42,0 39,5" 0,43 Mortality % 5,0 5,8 8,3 8,1 6,1 0,82 Haugh Unit 27 weeks 93,0 92,8 93,0 93,0 92,8 0,27 ' 41 " 83,7 84,3 84,2 84,1 84,4 0,33 " 63 " 74,8 76,2 76,3 75,4 77,3 0,47 Spec.gravity 27 weeks 1,0893 1,0905 1,0901 1,0905 1,0901 0,00026 41 " 1,0847 1,0852 1,0847 1,0854 1,0844 0,00026 63 1,0813 1,0817 1,0815 1,0817 1,0815 0,00032 a-b, P < 0,05 140-15- 130-120 - >' 16-110 - _c 100-90 - On e phase 0.1 phosw Three phases Three phazes 80 190 Two phases(b) 70 0 10 10 12 4 P ei0d 8 8 Period 10 12 Two phases(b) Fig. 3. Feed intake in Expt. 2. Fig. 4. Protein intake in Expt. 2. becomes particularly visible during.the second phase when the group was fed a diet with 9,7 MJ/kg and 11,6 % CP (Fig. 3). Feed conversion in the phased groups was 3-5 % poorer than in the control group but the differences were not significant. Daily protein supply was relatively low (Table 9, Fig. 4) and the differences between the constant feeding and phased feeding were significant (P <0,05). The use of phased feeding saved an average of 25 g protein in the production of one kilogram of eggs (P < 0,05). Daily ME intake of the phased groups was also lower than that in the control group but no significant differences could be ascertained in it or in the ME conversion. The differences in intake of nutrients between the supplementary protein treatments (IP, DP) were very slight. Final body weight and percentage weight gain of hens fed phased or DP diets were significantly (P <0,05) lower than those of the corresponding controls (Table 9). No significant differences in mortality were observed between the treatments. 3 408400402h 17

Table 9. Perforrnance and egg quality data for hens fed phased diets and different supplementary proteins (Expt. 2). Diet.ary regimen Number of phases 2(a) 2(b) 3 Supplemantary prorein1) IP DP SE Egg output (control) kg/housed hen 12,77 12,21 12,81 12,50 12,54 12,47 0,092 % 73,3 72,1 72,9 72,7 72,3 72,8 0,36 g/hen/day 42,9 41,7 42,1 41,8 41,8 41,9 0,26 Egg weight g 58,5 57,8 57,8 57,4 57,8 57,6 0,15 Feed intake g/h/d 114,4a 114,7a 117,7b 115,0a 115,7 115,9 0,42 " kg/kg eggs 2,67 2,75 2,80 276 2,77 2,77 0,014 Protein intake g/h/d16,3a 15,2b 14,5b 14,8b 14,7 14,9 0,11 g/kg eggs 381a 364b 345e 356be 353 357 2,5 ME intake KJ/h/d 1219 1191 1180 1174 1184 1179 4,4 " MJ/kg eggs 28,4 28,6 28,0 28,1 28,4 28,2 0,13 Final body weight 1921a 1829b 1822b 1771b 1829 1785 7,0 Weight 'gain % 36,7' 31,8b 30,0b 29,7b 32,0 29,0 0,40 Mortality % 7,2 Haugh unit 26 10,0 4,7 6,9 5,4 8,5 0,85 weeks 96,4 94,7 95,7 94,8 95,2 94,8 0,28 unit 46 weeks 79,6ab 80,0ab 77,7a 80,5b 79,2 79,3 0,34 Haugh Haugh unit 66 weeks 68,8 72,6 69,9 70,8 71,6 70,8 0,47 Spec,gravity 26 weeks 1,0899 1,0893 1,0891 1,0889 1,0893 1,0889 0,00024 Spec.gravity 46 weeks 1,0853a 1,0835b 1,08500 1,0842ab 1,0843 1,0842 0,00021 Spee.gravity 66 weeks 1,0813 1,0826 1,0831 1,0823 1,0827 1,0826 0,00026,..-c P < 0,05 1) ip = mainly imported protein ingredients tip= mainly domestic ingredients Feeding a diet containing domestic supplementary protein had no significant effect on the interior quality or shell strength of the eggs laid, as measured by Haugh units and specific gravity (Table 9). The second determination of egg quality (40 weeks) showed a lower HU for one of the two-phase groups (2 b) than for the other groups and the difference was significant (P <0,05) in comparison with the three-phase group. However the specific gravity of eggs in the other two-phase group (2 a) differed significantly (P <0,05) from that of the control group. Experiment 3. Chicks fed the 19 % protein and 11,7 MJ/kg finisher diet had a higher rate of weight gain (P <0,05) than those fed other diets, excluding birds on the other extreme diet with 15 % protein and 10,5 MJ ME/kg (Table 10). No significant differences were ascertained in growth results between the two ME:CP ratios and supplementary protein treatments. There were significant interactions (P <0,05) of supplementary protein x KJ/g CP and sex x KJ/g CP (Table 11). The average slaughter weights on the highest energy diets were bigger than on the other diets but a significant difference (P <0,05) was found only between the 11,7/19 and 11,1/16 diets. The daily feed intake (121-131,5 g) was very high and the ME-CP combination 10,5/15 differed significantly (P <0,05) from the combinations 11,1/18 and 11,7/19. The difference between the two ME:CP ratios was also significant (P < 0,05). Feed conversion of the 10,5/15 diet was significantly (P<0,05) poorer and that of the 11,7/19 diet significantly (P < 0,05) better than that of the other ME- CP combinations. Feed efficiency was better on the lower ME:CP ratio than on the higher ratio (P < 0,05). 18